Multifocal Laser Machining to Block Opposite-Side Light Damage
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Solution Overview
Problem
In laser processing, the side opposite to the laser light incidence side, particularly functional element layers, are at risk of damage due to non-modulated laser light during multifocal laser processing, where the laser light is branched into multiple rays, leading to potential damage from unabsorbed light.
Innovation Solution
A laser processing apparatus and method that employs a spatial light modulator to branch laser light into multiple rays with converging points positioned differently, ensuring the modified region formed by the 0th-order light is between the non-modulated light's converging point and the opposite surface, effectively blocking non-modulated light from reaching the opposite side, and the moving mechanism adjusts these points to maintain this configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multifocal laser processing is performed to peel off a part of the object, then the peeling-off processing is achieved, but the side of the object opposite to the laser light incidence side is significantly damaged by non-modulated light
Solution Approach 1:
The laser beam is segmented into multiple rays with different convergence points using a spatial light modulator. By dividing the single laser beam into multiple focused rays at different depths, the patent creates a modified region that blocks the harmful non-modulated light from reaching the opposite side while maintaining the peeling-off effect on the target surface.
Solution Approach 2:
A modified region is created as an intermediary structure between the laser incidence side and the opposite side. This modified region acts as a barrier that blocks the transmission of non-modulated light to the opposite side, thereby protecting functional elements while allowing the peeling-off process to proceed on the target surface.
2Object-affected harmful factors
If laser light is branched into multiple rays with different converging points, then the modified region is formed to block non-modulated light, but the device complexity increases due to spatial light modulator
Solution Approach 1:
The patent replaces complex mechanical optical path switching mechanisms with a spatial light modulator that uses electro-optic or acousto-optic effects to modulate the laser beam. This substitution reduces mechanical complexity while achieving the same function of creating multiple convergence points and blocking harmful light through controlled modification of the optical properties.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively prevents damage to the opposite side by blocking non-modulated laser light, reducing the risk of damage to functional element layers and allowing controlled peeling-off processes without harming the device layer, thereby curbing damage on the side opposite to the laser light incidence side.
Implementation Method 1
the irradiation unit has a spatial light modulator that modulates the laser light and a converging part that converges the laser light modulated by the spatial light modulator on the object
Implementation Method 2
a converging part that converges the laser light modulated by the spatial light modulator on the object
Implementation Method 3
This modified region can block the non-modulated light of the laser light such that the non-modulated light does not reach a side opposite to the laser light incidence side in the object
Data Source
AI summary
This laser processing apparatus includes an irradiation unit and a controller. The irradiation unit has a spatial light modulator and a converging part. The controller executes first control for causing the laser light to be modulated by the spatial light modulator such that the laser light is branched into a plurality of rays of processing light and a plurality of converging points of the plurality of rays of processing light are positioned in different positions in a direction perpendicular to an irradiation direction of the laser light. In the first control, the laser light is modulated such that the modified region is present between a converging point of non-modulated light of the laser light and an opposite surface on a side opposite to a laser light incidence surface of the object in the irradiation direction.